Seamless NURBs UVs?

[Krion]

Hi,

I thought that with the uvtexture SOP you would already have seamlessness when using the 'spline' methods.
Yet this is not the case. The 'Average Spline' comes closest, but it's not yet seamless.

How do we do it?

seamless-nurbs-uv.hiplc (the seam is on the positive X axis)

Thanks in advance.

Edited July 13, 2021 by Krion

[vinyvince]

Nurbs surfaces never have to be seamless.You could just make the parametrisation to be as uniform as possible and because nurbs surface are mathematicaly define , you don't need to project or unwrap to creat UV.

To seam in U and V is a totally different thing...

[Krion]

I don't know what that means.
It's a seamless texture that I apply. I don't understand what it would mean for a nurb surface to be seamless or non-seamless. It is no unwrap or project, because it uses the nurbs parametrisation (0-1?) to map the uv's unto, right?

I've made a more 'obviously' tileable texture in this hip file, so you can see the seam even more pronounced:   (seamless-nurbs-uv.v2.hiplc)

In my case I want it to map unto the nurbs/follow the nurbs shape, as these 'spline' methods of the uvtexture sop do, but how do I have a seamless texture go round-about it?

Edited July 24, 2021 by Krion

[Aizatulin]

Hi,

maybe as a workaround you can evaluate the (NURBS)surface itself by a grid, where the intrinsic uv is the same as the texture uv. Now you can fit the surface to get close to the original shape.

 

seamless-nurbs-uv.v2_mod.hipnc

Edited July 25, 2021 by Aizatulin

[vinyvince]

13 hours ago, Krion said:

I don't know what that means.
It's a seamless texture that I apply. I don't understand what it would mean for a nurb surface to be seamless or non-seamless. It is no unwrap or project, because it uses the nurbs parametrisation (0-1?) to map the uv's unto, right?

I've made a more 'obviously' tileable texture in this hip file, so you can see the seam even more pronounced:   (seamless-nurbs-uv.v2.hiplc)

In my case I want it to map unto the nurbs/follow the nurbs shape, as these 'spline' methods of the uvtexture sop do, but how do I have a seamless texture go round-about it?

 

I misunderstood your problem.

If you unchecked imperfect box in the sphere primitive, it will fix your issue

 

vincent.

[Krion]

On 25/07/2021 at 2:12 PM, vinyvince said:

If you unchecked imperfect box in the sphere primitive,

Interesting. Any way that translates when you're using a Skin SOP to create the NURBs surface?  -  (as here: seamless-nurbs-uv.v3.skinMethod.hiplc)

(this is how I originally am creating the surface in my scene. but I used a Sphere SOP for simplicity because I thought this was a general NURBs issue)

 

Edited July 26, 2021 by Krion